Please correct my macro.

Line1 is OK
LastLine - The worksheet "flickers" (like doing a loop) for about 5 seconds.

Private Sub Worksheet_SelectionChange(ByVal Target As Range)

If ActiveCell = "$G$5" Then GoTo Line1
If ActiveCell = "$L$5" Then GoTo LastLine


Line1:
If Intersect(Target, Me.Range("G5")) Is Nothing Then
'do nothing

Else

Selection.RemoveSubtotal
Range("A5").Select

End If


LastLine:
If Intersect(Target, Me.Range("L5")) Is Nothing Then
'do nothing


Else

Selection.Subtotal GroupBy:=1, Function:=xlSum, TotalList:=Array(3, 4, 5, 6, _
7, 8, 9, 10, 11, 12), Replace:=True, PageBreaks:=False,
SummaryBelowData:=True
Range("A5").Select

End If
End Sub

Whats wrong with it?

Thanks